The aim of this investigation is to determine the effect of an acousto-optic deflector (AOD) on the spatial and temporal characteristics of ultra-short (ps) radiation pulses of near - IR radiation (800 nm). This information is to be used to establish the feasibility of using the AOD in a multi-photon laser scanning microscope (MPLSM). The interest of using an AOD in an WLSM is in its ability to do fast imaging of live samples or dynamic events without the photodamage of single-photon fluorescence imaging.